Apparatus and method for mail sorting

Abstract

A method for sorting mail to a case having a plurality of slots is described, wherein each slot corresponds to a destination. The method includes steps of loading a mail piece to be sorted into a delivery robot, determining for the mail piece a destination slot the mail piece is to be delivered to, moving the delivery robot along a rail disposed at the front of the case near the slots into proximity with an open end of the destination slot, inserting the mail piece from the delivery robot into the associated slot, and returning the delivery robot to a loading station whereby the cycle may be repeated. Such a method, when using a large number of robots moving along a common rail system, can sort a large volume of mail in carrier delivery order.

1. A method for sorting mail to a case having a row of upright slots, wherein each slot corresponds to a destination, comprising:
 (a) loading a mail piece to be sorted into a delivery robot; 
 (b) determining for the mail piece a destination slot the mail piece is to be delivered to; 
 (c) moving the delivery robot along a rail disposed at the front side of the case near the slots into proximity with an open end of the destination slot; 
 (d) holding the mail piece in an insertion mechanism while extending the insertion mechanism from the robot into the slot; 
 (e) releasing the mail piece from the insertion mechanism while both the insertion mechanism and mail piece are in the slot; 
 (e) retracting the insertion mechanism from the slot; 
 (f) preventing contact between the mail piece and the retracting insertion mechanism from causing the mail piece to be pulled out of the slot with the retracting insertion mechanism; and 
 (g) returning the delivery robot to a loading station whereby steps (a)–(e) may be repeated. 
 
     
     
       2. The method of  claim 1  wherein the delivery robot moves horizontally along a rail mounted to the side of a horizontal row of upright slots that receive mail pieces from the delivery robot through the open front sides thereof. 
     
     
       3. The method of  claim 1 , wherein the insertion mechanism includes a pair of flat plates that cover the mail piece from opposite sides. 
     
     
       4. The method of  claim 3 , wherein the insertion mechanism has movable surface elements disposed on the flat plates that move with the mail piece until the mail piece exits from a front end opening of the insertion mechanism. 
     
     
       5. The method of  claim 4 , wherein the mail piece is first inserted into the slot and then the insertion mechanism is withdrawn in a manner that leaves the mail piece behind. 
     
     
       6. The method of  claim 5 , wherein the surface element comprises a belt wound about one of the flat plates, and the insertion mechanism includes a belt engaging element that moves the belt around the plate, whereby an inner side of the belt moves with the mail piece during the step of inserting the mail piece. 
     
     
       7. The method of  claim 1 , further comprising preventing mail pieces already present in the slot from being pulled out of the slot along with the insertion mechanism during the retracting step. 
     
     
       8. The method of  claim 7 , further comprising a step of forming a space for the insertion mechanism to enter the slot without contacting mail pieces already present in that slot. 
     
     
       9. The method of  claim 8 , wherein the step of forming a space further comprises:
 inserting a guide into each slot before sorting to the slots; 
 inserting the mail piece to one side of the guide; and 
 repositioning the guide on the opposite side of the mail piece just inserted, so that another mail piece may be inserted between the guide and one side of the slot. 
 
     
     
       10. The method of  claim 9 , wherein the insertion mechanism includes a pair of flat plates that cover the mail piece from opposite sides and has a movable surface element disposed on at least one of the flat plates that moves with the mail piece until the mail piece exits from a front end opening of the insertion mechanism, and the preventing step further comprises, after the step of repositioning the guide, moving the movable surface element along the outside of the plate adjoining mail already present in the slot so that the surface element does not slide relative to mail already present in the slot. 
     
     
       11. The method of  claim 1  further comprising, prior to step (a):
 scanning destination information from each mail piece to be transferred to a slot; and 
 storing the scanned information on a computer for use in step (b). 
 
     
     
       12. The method of  claim 11 , further comprising downloading to a controller on the delivery robot instructions identifying the destination slot, whereby the controller actuates the insertion mechanism upon reaching the destination slot to perform step (c). 
     
     
       13. The method of  claim 12 , further comprising, prior to step (c), a step of detecting the destination slot by using a sensor on the delivery robot connected to the controller, which sensor reads indicia proximate the slot identifying the slot as the destination slot. 
     
     
       14. The method of  claim 13 , wherein step (c) further comprises:
 moving the delivery robot along the rail; 
 scanning a slot identifying indicia disposed proximate each slot the delivery robot passes with a scanner mounted on the delivery robot; 
 if the scanned slot is the one determined in step (b), then stopping the delivery robot at that slot. 
 
     
     
       15. The method of  claim 1 , wherein the slots comprise mouths of a row of flexible bags, which bags have been mounted on the case, further comprising positioning a stiffening frame in front of the row of flexible bags so that stiffening plates of the frame extend into the mouths of each of the bags. 
     
     
       16. The method of  claim 1 , wherein the slots comprise spaced vertical dividers secured to the case to form slots having fixed widths. 
     
     
       17. The method of  claim 1 , wherein the slots comprise spaced vertical dividers inserted into the case but not secured thereto. 
     
     
       18. The method of  claim 17 , wherein the spaced vertical dividers are disposed in a tray having an open side, which tray is removably placed in the case. 
     
     
       19. An automated system for sorting a series of mail pieces, comprising:
 a rail system including a loop; 
 a number of mail piece delivery robots mounted on the rail for movement along the loop, each delivery robot having an insertion mechanism that can receive a mail piece therein and then insert it into an open side of a destination slot; 
 an automated loading station including a conveyor having a loading end at which a mail piece exits the conveyer and enters the insertion mechanism of a delivery robot positioned on the rail in alignment with the loading station; 
 a case disposed along the rail having a row of the destination slots for receiving mail sorted thereto for a plurality of destinations; 
 means for moving the delivery robots from the loading station to the case and back to the loading station on the loop; 
 a control system that coordinates movement of the delivery robots so that each delivery robot moves from the loading station to a slot which corresponds to a destination indicated on the mail piece and then returns to the loading station to receive another mail piece for sorting; and 
 a proximity sensor mounted on each delivery robot, the proximity sensor detecting another delivery robot ahead of the robot on which the sensor is mounted within a predetermined distance, and communicating with the control system to prevent collisions between delivery robots. 
 
     
     
       20. The system of  claim 19 , wherein the control system comprises control units on each inserter and means for transmitting slot delivery instructions to each inserter control unit. 
     
     
       21. The system of  claim 19 , further comprising a loading rack mounting a plurality of moveable guides configured for insertion into the case. 
     
     
       22. The system of  claim 21 , wherein the loading rack further mounts a plurality of partitions paired with the moveable guides, so that a partition and guide are inserted into the case for each sorting destination. 
     
     
       23. The system of  claim 22 , wherein the moveable guides and partitions are mounted on a movable guide frame, the guide frame being mounted on the loading rack for inserting the guides and partitions into a horizontal shelf of the case. 
     
     
       24. The system of  claim 19 , further comprising an emergency transmitter mounted on each delivery robot, which emergency transmitter communicates with the control system upon detection of one or more predetermined fault conditions. 
     
     
       25. The system of  claim 9 , wherein the insertion mechanism includes a drive system whereby the insertion mechanism can be extended from and retracted back into the delivery robot. 
     
     
       26. An automated system for sorting a series of mail pieces, comprising:
 a rail system including a loop; 
 a number of self-propelled delivery robots mounted on the rail for movement along the loop, each of the robots including an onboard drive system and power source for moving the robot along the loop, each delivery robot having an insertion mechanism that can receive a mail piece therein and then insert it into an open side of a destination slot; 
 an automated loading station including a conveyor having a loading end at which a mail piece exits the conveyor and enters the insertion mechanism of a delivery robot positioned on the rail in alignment with the loading station; 
 a case disposed along the rail having a row of the destination slots for receiving mail sorted thereto for a plurality of destinations; and 
 a control system that coordinates movement of the delivery robots so that each delivery robot moves from the loading station to a slot which corresponds to a destination indicated on the mail piece and then returns to the loading station to receive another mail piece for sorting.